Re: overloading times operator
- To: mathgroup at smc.vnet.net
- Subject: [mg88830] Re: overloading times operator
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Sat, 17 May 2008 23:29:12 -0400 (EDT)
- References: <g0m918$3n$1@smc.vnet.net>
Hi, it's frustrating to repeat, that we can only answer a question when we get the full code and *not* a mixture of Mathematica and TeX and not a description like "wrote a procedure to define the non-commutative product" because the problem is probably in that "procedure to define the non-commutative product" and we can't help you if you don't write how this "procedure to define the non-commutative product" is defined. Regards Jens gstaples wrote: > I wrote a procedure to define the non-commutative product of two elements of the form e_X e_Y, where X and Y are multi-indices. I do this using Times. > > I do a simple calculation like > > Expand[(e_{1} + e_{3})(e_{1} - e_{3})] > > and get the wrong answer. (On the first try.) > > If I then re-execute the code that defines the multiplication, I repeat the calculation and get correct output. > > Alternatively, if I execute > > e=Symbol["e"] > > before loading the procedure, I get correct output on the first try. > > More troubling is that after getting correct output, if I perform calculations of a different kind (e.g. matrix multiplication), when I repeat my original calculation, I start getting incorrect output again. (Until I re-execute the code that defines the multiplication.) > > It's frustrating to repeat a calculation and get different sets of output depending on what other calculations are done in between. > > Does anyone have suggestions? >